Adding the yes(1) command.

yes.c

@@ -0,0 +1,44 @@
+/* See LICENSE file for copyright and license details. */
+#include <unistd.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "arg.h"
+#include "util.h"
+
+char *argv0;
+
+void
+usage(void)
+{
+	eprintf("usage: %s [string ...]\n", basename(argv0));
+}
+
+int
+main(int argc, char *argv[])
+{
+	int i;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (!argc) {
+		for(;;)
+			puts("y");
+	}
+
+	for (;;) {
+		for (i = 0; i < argc; i++) {
+			fputs(argv[i], stdout);
+			if (argv[i+1] != NULL)
+				fputs(" ", stdout);
+		}
+		fputs("\n", stdout);
+	}
+
+	return EXIT_SUCCESS;
+}
+